<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8>
    <meta name="viewport" content="width=device-width, initial-scale=1.e">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>v-if指令</title>
    <style>
        .active {
            border: 1px solid red;
        }
    </style>
</head>

<body>
    <div id="app">
        <!-- 完整写法 -->
        <img v-bind:src="imgSrc" />
        <br/>
        <!-- 简写 -->
        <img :src="imgSrc" :title="imgTitle+'!!!'"
             :class="isActive?'active':''" @click="toggleActive" />
        <br/>
        <!-- 建议对象方式的写法 -->
        <img :src="imgSrc" :title="imgTitle+'!!!'"
             :class="{active:isActive}" @click="toggleActive" />
    </div>
    
    <!-- 开发环境版本，包含了有帮助的命令行警告 -->
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
    <script>
        var app = new Vue({
            el: "#app",
            data: {
                imgSrc: "http://www.itheima.com/images/logo.png",
                imgTitle: "黑马程序员",
                isActive: false
            },
            methods: {
                toggleActive: function() {
                    this.isActive = !this.isActive;
                }
            }
        })
    </script>
</body>
</html>